add the ConvexHull class

Android.mk

@@ -83,6 +83,7 @@ $(N)/glue/co/ContactListener.cpp \
 $(N)/glue/co/ContactManifold.cpp \
 $(N)/glue/co/ContactSettings.cpp \
 $(N)/glue/co/ConvexHullBuilder.cpp \
+$(N)/glue/co/ConvexHull.cpp \
 $(N)/glue/co/ConvexHullShape.cpp \
 $(N)/glue/co/ConvexHullShapeSettings.cpp \
 $(N)/glue/co/ConvexShape.cpp \

src/main/java/com/github/stephengold/joltjni/vhacd/ConvexHull.java

@@ -0,0 +1,94 @@
+/*
+Copyright (c) 2025 Stephen Gold
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+ */
+package com.github.stephengold.joltjni.vhacd;
+
+import com.github.stephengold.joltjni.Jolt;
+import com.github.stephengold.joltjni.JoltPhysicsObject;
+import java.nio.FloatBuffer;
+
+/**
+ * An immutable 3-D convex hull generated by the V-HACD algorithm. (native
+ * class: {@code IVHACD::ConvexHull})
+ */
+public class ConvexHull extends JoltPhysicsObject {
+    // *************************************************************************
+    // constants
+
+    /**
+     * number of axes in the coordinate system
+     */
+    final private static int numAxes = 3;
+    // *************************************************************************
+    // constructors
+
+    /**
+     * Instantiate a hull with the specified native object assigned.
+     *
+     * @param hullVa the virtual address of the native object to assign (not
+     * zero)
+     * @param owner {@code true} → make the JVM object the owner,
+     * {@code false} → it isn't the owner
+     */
+    ConvexHull(long hullVa, boolean owner) {
+        Runnable freeingAction = owner ? () -> free(hullVa) : null;
+        setVirtualAddress(hullVa, freeingAction);
+    }
+    // *************************************************************************
+    // new methods exposed
+
+    /**
+     * Count the points.
+     *
+     * @return the count (≥1)
+     */
+    public int countPoints() {
+        long hullVa = va();
+        int result = countPoints(hullVa);
+
+        return result;
+    }
+
+    /**
+     * Copy the point locations to a new direct buffer.
+     *
+     * @return the new buffer (capacity a positive multiple of 3)
+     */
+    public FloatBuffer getPointsAsBuffer() {
+        long hullVa = va();
+        int numPoints = countPoints(hullVa);
+        int numFloats = numPoints * numAxes;
+        assert numFloats > 0 : numFloats;
+
+        FloatBuffer result = Jolt.newDirectFloatBuffer(numFloats);
+        copyPoints(hullVa, result);
+
+        return result;
+    }
+    // *************************************************************************
+    // native private methods
+
+    native private static void copyPoints(long hullVa, FloatBuffer result);
+
+    native private static int countPoints(long hullVa);
+
+    native private static void free(long hullVa);
+}

src/main/native/glue/co/ConvexHull.cpp

@@ -0,0 +1,83 @@
+/*
+Copyright (c) 2025 Stephen Gold
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+ */
+
+/*
+ * Author: Stephen Gold
+ */
+#include "Jolt/Jolt.h"
+#include "VHACD.h"
+#include "auto/com_github_stephengold_joltjni_vhacd_ConvexHull.h"
+#include "glue/glue.h"
+
+using namespace VHACD;
+
+/*
+ * Class:     com_github_stephengold_joltjni_vhacd_ConvexHull
+ * Method:    copyPoints
+ * Signature: (JLjava/nio/FloatBuffer;)V
+ */
+JNIEXPORT void JNICALL Java_com_github_stephengold_joltjni_vhacd_ConvexHull_copyPoints
+  (JNIEnv *pEnv, jclass, jlong hullVa, jobject resultBuffer) {
+    const IVHACD::ConvexHull * const pHull
+            = reinterpret_cast<IVHACD::ConvexHull *> (hullVa);
+    jfloat * const pPoints
+            = (jfloat *) pEnv->GetDirectBufferAddress(resultBuffer);
+    JPH_ASSERT(!pEnv->ExceptionCheck());
+    const jlong capacityFloats = pEnv->GetDirectBufferCapacity(resultBuffer);
+    JPH_ASSERT(!pEnv->ExceptionCheck());
+    const size_t numPoints = pHull->m_points.size();
+    for (size_t i = 0; i < numPoints; ++i) {
+        const size_t baseIndex = 3 * i;
+        if (baseIndex + 2 >= capacityFloats) {
+            break;
+        }
+        pPoints[baseIndex] = pHull->m_points[i].mX;
+        pPoints[baseIndex + 1] = pHull->m_points[i].mY;
+        pPoints[baseIndex + 2] = pHull->m_points[i].mZ;
+    }
+}
+
+/*
+ * Class:     com_github_stephengold_joltjni_vhacd_ConvexHull
+ * Method:    countPoints
+ * Signature: (J)I
+ */
+JNIEXPORT jint JNICALL Java_com_github_stephengold_joltjni_vhacd_ConvexHull_countPoints
+  (JNIEnv *, jclass, jlong hullVa) {
+    const IVHACD::ConvexHull * const pHull
+            = reinterpret_cast<IVHACD::ConvexHull *> (hullVa);
+    size_t result = pHull->m_points.size();
+    return result;
+}
+
+/*
+ * Class:     com_github_stephengold_joltjni_vhacd_ConvexHull
+ * Method:    free
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL Java_com_github_stephengold_joltjni_vhacd_ConvexHull_free
+  (JNIEnv *, jclass, jlong hullVa) {
+    IVHACD::ConvexHull * const pHull
+            = reinterpret_cast<IVHACD::ConvexHull *> (hullVa);
+    TRACE_DELETE("IVHACD::ConvexHull", pHull)
+    delete pHull;
+}